What is a mini stroke?
A transient ischaemic attack (TIA) or 'mini stroke' is caused by a temporary disruption in the blood supply to part of the brain.
The disruption in blood supply results in a lack of oxygen to the brain. This can cause symptoms similar to those of a stroke, such as speech and visual disturbance and numbness or weakness in the arms and legs.
However, a TIA does not last as long a stroke. The effects only last for a few minutes and are usually fully resolved within 24 hours.
The main signs and symptoms of a TIA can be identified by remembering the word F.A.S.T., which stands for Face-Arms-Speech-Time.
- Face – the face may have fallen on one side, the person may be unable to smile, or their mouth or eye may have dropped
- Arms – the person may not be able to raise both their arms and keep them there due to weakness or numbness in their arms
- Speech – the person may have slurred speech
- Time – if any of these signs or symptoms are present, it is time to dial for an ambulance immediately
If the above signs and symptoms last longer than 24 hours, it is regarded as a full stroke.
It is important that a person who has a TIA is checked and treated as soon as possible to minimise the risk of having a further TIA or a full stroke. With treatment, the risk of a further TIA or full stroke can be greatly reduced.
Read more about how to recognise the signs and symptoms of a TIA.
What causes a TIA?
During a TIA, one of the small blood vessels that supply your brain with oxygen-rich blood becomes blocked.
Atherosclerosis is a common cause of narrowed arteries. It occurs when fatty deposits, known as plaques, develop on the inner lining of your blood vessels. This can cause your blood vessels to become thickened, hard and less elastic, making it more difficult for blood to flow through them.
A TIA can also occur as a result of a blood clot that forms in a blood vessel and blocks the blood supply to your brain.
In rare cases, a TIA can be caused by a small amount of bleeding in the brain, known as a haemorrhage.
Read more about the causes of TIA.
Diagnosing a TIA
As TIAs are often over quickly, you may not have any symptoms by the time you see a healthcare professional.
You will be asked in detail about the symptoms you experienced during the TIA. For example, how long they lasted and how they affected you. This will help rule out other conditions.
If a TIA is suspected, you should be referred within seven days of the TIA to a specialist for tests.
Read more about diagnosing a TIA.
Treating a TIA
Following a TIA, you will need treatment to help prevent another TIA or a full stroke.
Your treatment will depend on your individual circumstances, such as your age and medical history.Your healthcare team will discuss the treatment options with you, and tell you about possible benefits and risks.
You may be given medication or asked to make changes to your lifestyle (see the prevention advice below). In some cases, surgery may be needed.
Read more about how TIAs are treated.
Preventing a TIA
TIAs often occur without warning. If you have a TIA, it is a sign another one may follow and further TIAs can have more serious effects or develop into a full, life-threatening stroke.
Regardless of whether or not you have had a TIA or stroke in the past, there are a number of ways you can lower your risk of having either in the future. These include:
- maintaining a [healthy weight]
- [eating healthily ]
- taking [regular exercise]
- limiting your [alcohol] consumption
- not [smoking]
Read more about how lifestyle factors can help prevent a TIA.
Mini stroke symptoms
You can identify the main symptoms of a transient ischaemic attack (TIA) by remembering the word F.A.S.T. (Face-Arms-Speech-Time).
- Face – the person's face may have fallen on one side, they may be unable to smile and their mouth or eye may drop
- Arms – the person may not be able to raise both their arms and keep them raised due to arm weakness or numbness
- Speech – the person may have slurred speech
- Time – if any of these signs or symptoms are present, call for an ambulance immediately
Everyone should be aware of the signs and symptoms of a TIA or stroke. If you live with, or care for, someone in a high-risk group, such as an elderly person or someone with diabetes or high blood pressure, being aware of the symptoms is even more important.
The signs and symptoms in the F.A.S.T. test (above) can help you identify most TIAs and strokes. However, other signs and symptoms may include:
- sudden loss of vision
- communication problems, such as difficulty talking or understanding what others are saying
- balance and co-ordination problems
- difficulty swallowing (dysphagia)
- numbness or weakness, resulting in complete paralysis (loss of the ability to move one or more muscles) in one side of the body
- in severe cases, loss of consciousness
Duration of TIA symptoms
As the name suggests, the symptoms of a TIA are transient (temporary) and should clear up within 24 hours of the attack. The exact duration of symptoms may vary, but they often disappear within one hour.
Different parts of your brain control different parts of your body, so the symptoms that you will have after a TIA will depend on the part of your brain that is affected.
Sometimes, a TIA will occur before a full stroke, which can cause serious and permanent damage. Therefore, the sooner medical attention is sought, the less likely another TIA or a stroke will occur.
Mini stroke causes
During a transient ischaemic attack (TIA), one of the small blood vessels that supply your brain with oxygen-rich blood becomes blocked.
Blood is supplied to your brain by two main blood vessels (carotid arteries) and two other blood vessels (vertebral arteries). These arteries branch off into a series of smaller blood vessels that supply blood to every part of your brain.
If a blood vessel becomes blocked, the blood flow to your brain will be disrupted. In TIAs, the disruption quickly passes and your brain's blood supply soon returns to normal. In a full stroke, blood flow to your brain is disrupted for much longer. Without a constant supply of blood, your brain cells will begin to die.
The blockage in your blood vessels is usually caused by a narrowing of the arteries, or as a result of a blood clot that has formed elsewhere in your body and travelled to your brain.
Atherosclerosis is a condition that causes narrowing of the arteries. It occurs when fatty deposits, known as plaques, develop on the inner lining of your blood vessels.
This can cause your blood vessels to become thickened, hard and less elastic, making it more difficult for blood to flow through them.
Read more about atherosclerosis.
A TIA can also occur when a blood clot develops in a blood vessel and blocks the blood supply to your brain.
Blood clots can be caused by a number of different factors including:
- heart conditions – such as atrial fibrillation, which causes your heart to beat irregularly, or congestive heart muscle disease where your heart does not pump blood effectively
- blood conditions – such as leukaemia (cancer of the blood cells), sickle cell anaemia (an inherited blood disorder), high levels of fat in your blood (hyperlipidaemia), abnormally thickened blood (polycythaemia), or overproduction of platelets in your blood (thrombocythaemia)
A TIA can sometimes occur when a blood clot from a blood vessel in another part of your body moves into one of the arteries that supply blood to your brain. This is known as an embolism.
In very rare cases, a TIA can be caused by a small amount of bleeding in the brain. This is known as a haemorrhage.
A number of factors can increase your chances of having a TIA. These risk factors can either be:
- fixed – such as age and gender
- changeable – by altering your lifestyle, you may be able to reduce your risk of having a TIA
Some of the fixed risk factors associated with TIA are outlined below.
As you get older, your arteries begin to harden and narrow, increasing your risk of having a TIA.
TIAs most commonly occur in people over 60 years of age, although they can occur at any age, including in children and young adults.
Men have a higher risk of having a TIA compared with pre-menopausal women. The risk of having a TIA or stroke increases in post-menopausal women.
It is not fully understood why the risk of having a TIA increases following the menopause (when a woman's monthly periods stop). However, the female hormones, oestrogen and progesterone, are thought to play a role as they can affect elasticity of the blood vessels.
In menopausal women, oestrogen and progesterone levels fall, which may cause the blood vessels to become harder and less elastic.
If you have a family history of stroke or TIA, your risk of having a TIA is increased. However, the risk is relatively small and having family members who have had a TIA will not necessarily mean that you will have one.
High blood pressure
High blood pressure (hypertension) is the most significant risk factor associated with TIA. Having high blood pressure puts extra strain on your body's blood vessels, causing them to become narrowed or clogged.
Weight and diet
A diet high in [saturated fat] increases your risk of developing atherosclerosis. If there is too much [salt] in your diet, it is likely your blood pressure will be elevated which, like atherosclerosis, is a major risk factor for TIA.
Being overweight also puts your heart under strain and weakens your blood vessels.
Smoking can double your risk of having a TIA or stroke. The harmful chemicals in cigarette smoke cause the lining in the arteries to thicken, which makes your blood more likely to clot.
Therefore, [stopping smoking] (if you smoke) is one of the main ways of preventing a TIA or stroke.
Read about how to lower your risk of having a TIA.
Diabetes causes high levels of glucose to develop in your bloodstream, which increases your risk of developing atherosclerosis (see above).
Diagnosing a mini stroke
Seek immediate medical assistance if you or someone you know is displaying the signs and symptoms of a transient ischaemic attack (TIA).
Receiving medical attention as soon as possible after having a TIA will lower the risk of having a further TIA or a full stroke.
TIAs are often over very quickly, so you may not have any symptoms by the time you see your doctor or another healthcare professional.
Your healthcare professional will ask about the symptoms you experienced during the TIA. For example, they will want to know how long the symptoms lasted and how they affected you. This information will help them rule out other conditions that may have caused your symptoms.
Even if you no longer have symptoms, the healthcare professional carrying out your assessment may still need to carry out a neurological examination. This will involve doing a series of simple tasks to check power, sensation and co-ordination skills.
If the healthcare professional who assesses you suspects you have had a TIA, they will refer you immediately to a specialist for further testing.
It is likely you will be referred to a neurologist (a doctor who specialises in conditions that affect the brain and spine), or a consultant who specialises in strokes. Alternatively, you may be referred to a specialist TIA clinic. These are available at some hospitals and doctor surgeries.
You should be referred to a specialist or TIA clinic within seven days of having a TIA. If you have had more than one TIA in a seven-day period, you should be seen immediately by a specialist.
Following a TIA, you may have a number of tests to check for any underlying factors or conditions that may have caused your mini stroke. Some of these tests are described below.
If you have had a TIA, you might need a series of blood tests such as a:
- blood pressure test – your blood pressure will be checked because high blood pressure (hypertension) is a major risk factor for TIA and stroke
- blood clotting test – your blood clotting ability will be tested to check how ‘thin’ your blood is and how likely it is to clot
- cholesterol test – a serum cholesterol test may be used to check your cholesterol levels; if you have high cholesterol, you are at greater risk of having a TIA or stroke
- glucose test – your blood glucose level will be checked; high levels of blood glucose may indicate you have diabetes
An electrocardiogram (ECG) is a test that measures your heart's electrical activity using a number of electrodes (small, metallic discs) attached to your skin.
An ECG can detect any abnormal heart rhythms, which may be a sign of conditions such as atrial fibrillation (where your heart beats irregularly).
You may have a chest X-ray to help rule out any other health conditions.
A computerised tomography (CT) scan uses a series of X-rays to produce an image of the inside of your body. It can be used to check for other factors that may have caused your TIA, such as a haemorrhage (bleed) or tumour (growth).
Like a CT scan, a magnetic resonance imaging (MRI) scan produces an image of the inside of your body, but instead of using X-rays it uses a strong magnetic field and radio waves. An MRI scan may be able to give a more detailed image of the brain and blood vessels than a CT scan.
An ultrasound scan uses high-frequency sound waves to produce an image of the inside of your body. You may have an ultrasound scan of the carotid arteries in your neck to find out whether they are narrowed or blocked. This type of ultrasound scan is sometimes known as a Doppler scan or a Duplex scan.
An echocardiogram can be used to produce an image of your heart and can highlight various forms of heart disease.
Treatment for a mini stroke
After having a transient ischaemic attack (TIA), you will need treatment to help prevent another TIA or full stroke from occurring in the future.
Without treatment, there is a one in 10 chance that you will have a full stroke within four weeks of having a TIA. A stroke is a serious health condition that can cause permanent disability and can, in some cases, be fatal.
Your treatment will depend on your individual circumstances, such as your age and medical history.The healthcare team can discuss treatment options with you, and tell you about possible benefits and risks.
To reduce the risk of further TIAs or stroke, you may be prescribed medication and be advised to make changes to your lifestyle.
Read more about how lifestyle changes can help prevent a TIA.
Some people may also need surgery as part of their treatment programme.
Platelets are blood cells that help it to clot (thicken). If a blood vessel is damaged, platelets stick together to form a blood clot to prevent bleeding.
Anti-platelet medicines work by reducing the ability of the platelets to stick together and form clots. If you have had a TIA, it is likely you will need anti-platelet medication.
The most commonly prescribed anti-platelet medicines for preventing a TIA, plus two other types of medication, are described below.
Aspirin and dipyridamole
Aspirin is the most commonly prescribed anti-platelet medicine. It is often taken with another anti-platelet medicine called dipyridamole.
Aspirin and dipyridamole are often prescribed together because they are more effective at preventing TIAs and strokes when used in combination compared to when taken separately.
Following a TIA, you will usually be prescribed aspirin and dipyridamole for two years. After this time, you may be able to stop taking dipyridamole and take a low-dose aspirin instead.
Depending on what your doctor thinks is the best treatment for you, you may need to take low-dose aspirin indefinitely. A daily low dose of aspirin is thought to reduce your risk of having a TIA by 25%. It can also reduce your risk of having a heart attack.
Side effects of aspirin may include:
- stomach irritation
Side effects of dipyridamole may include:
Clopidogrel is another anti-platelet medicine. It is usually only prescribed if you have:
- severe side effects from taking aspirin
- had a further TIA, despite taking aspirin
- arterial disease
Side effects of clopidogrel may include:
- abdominal pain
Anti-coagulant medicines work by reducing the level of certain chemicals in your blood needed to help the blood to clot.
You will usually only be prescribed an anti-coagulant medicine if the blood clot that caused your TIA originated in your heart. This is often due to a condition called atrial fibrillation, which causes your heart to beat irregularly
Warfarin is the anti-coagulant medicine used to help prevent further TIAs.
It is important that you receive the correct dose of warfarin. It must be enough to ensure your blood is ‘thinner’ (less able to clot), but it should not be so thin that it causes problems, such as internal bleeding.
Your condition will be carefully monitored while you are taking warfarin. You will need regular blood tests, known as international normalised ratio (INR) tests.
An INR test measures how long it takes your blood to clot. Your warfarin dosage may have to be adjusted after an INR test to ensure you are getting the right amount.
Bleeding is the most serious side effect of warfarin. Seek immediate medical attention if you notice any of the following symptoms while taking warfarin:
- passing blood in your urine or stools (faeces)
- passing black faeces
- severe bruising
- prolonged nosebleeds (lasting more than 10 minutes)
- blood in your vomit
- coughing up blood
- unusual headaches
- in women, heavy periods or increased bleeding during your period, or any other bleeding from your vagina
If you are unable to tolerate warfarin, you may be prescribed an oral anti-coagulant medicine, such as [dabigatran].
Blood pressure medication
If you have high blood pressure (hypertension), you may have to take medication to control it. This is because high blood pressure significantly increases your risk of having a TIA or stroke.
There are lots of different types of medicine that can help control your blood pressure. Your doctor will advise you about which one is the most suitable for you. To be effective, some people have to take a combination of two or three different blood pressure medicines.
High cholesterol is another factor that may increase your risk of having a TIA. You can lower your cholesterol by making certain lifestyle changes, such as eating a healthy, balanced diet.
Read more about making important lifestyle changes to help prevent a TIA.
If your cholesterol level needs to be lowered with medication, you will usually be prescribed a type of medicine known as a statin. Statins help reduce the production of cholesterol in your liver.
In some cases, you may need surgery after having a TIA or stroke. A procedure known as a carotid endarterectomy is commonly used.
A carotid endarterectomy is a surgical procedure that involves removing part of the lining of the damaged carotid artery, plus any blockage that has built up in the artery.
The carotid arteries deliver blood to your brain. When fatty deposits build up inside the carotid arteries, they become hard and narrow, making it more difficult for blood to flow through them. This is known as atherosclerosis.
If you have atherosclerosis, you may need a carotid endarterectomy to help reduce your risk of having a further TIA or stroke.
However, carotid endarterectomies are not suitable for everyone with atherosclerosis. For example, if your arteries are almost completely blocked, the procedure is unlikely to work.
If your carotid arteries are only partially blocked, you may also be unsuitable for this type of surgery because your risk of having a stroke during the procedure may outweigh the potential benefits of surgery.
A carotid endarterectomy is most suitable for people who have a moderate to severe blockage in their arteries. In such cases, the procedure can reduce the risk of further TIAs and strokes by more than a half.
Preventing a mini stroke
A transient ischaemic attack (TIA) often occurs without warning. Having a TIA may be a sign that another one could follow.
Further TIAs may have more serious effects, or develop into a full, life-threatening stroke.
Whether or not you have previously had a TIA or stroke, there are steps you can take to lower your risk of having either in the future. These are outlined below.
[Losing excess weight] will reduce your chances of having a TIA or stroke.
Regular exercise can lower your blood pressure, which will help prevent many potentially life-threatening conditions, including stroke, heart disease and cancer. It is also an effective way of maintaining a healthy weight, and can help combat [stress, anxiety and depression].
You should aim to do at least 150 minutes (2 hours and 30 minutes) of moderate-intensity aerobic activity, such as cycling or brisk walking, every week.
Eating a healthy, balanced diet will help you lose excess weight, and also keep your arteries healthy.
Make sure you eat plenty of fruit and vegetables (at least five portions a day) because they are a great source of essential vitamins and minerals.
Fruit and vegetables also contain substances called anti-oxidants, which reduce the risk of stroke by protecting the walls of your blood vessels from damage.
Limit the amount of salt you eat to no more than 6g a day (about one full teaspoon). Too much salt can raise your blood pressure, which increases your risk of TIA and stroke.
Do not add salt to your food, and be aware that lots of processed foods include ‘hidden’ salt. Therefore, always check the nutritional information on the label before buying food products.
Limiting the amount of saturated fats in your diet will help to keep your cholesterol under control. Foods high in saturated fats include:
- meat pies
- sausages and fatty cuts of meat
- ghee (a type of butter often used in Indian cooking)
- hard cheese
- cakes and biscuits
- foods containing coconut or palm oil
If you eat a lot of fatty foods, your arteries are more likely to get clogged with fatty deposits (plaques).
Drinking too much alcohol may increase your risk of having a TIA or stroke. Therefore, you should stay within the recommended limits of alcohol which are:
- 2-3 units a day for women
- 3-4 units a day for men
One unit of alcohol is equal to about half a pint of normal-strength lager, cider or bitter, a pub measure (25ml) of spirits, or a 50ml pub measure of fortified wine, such as sherry or port.
If you have had a TIA, you do not need to cut out alcohol altogether. Some studies have suggested drinking a small amount of alcohol (within the recommended daily amount) may actually reduce your risk of having a TIA or stroke. This is because alcohol can thin the blood.
However, always avoid binge drinking. Drinking too much alcohol is likely to raise your blood pressure. It also increases the risk of a blood vessel bursting and causing bleeding into your brain. This, in turn, will increase your risk of having a TIA or stroke.
Smoking doubles your risk of having a stroke. This is because it narrows your arteries and makes your blood more likely to clot.
If you stop smoking, you can reduce your risk of having a stroke by up to half. Not smoking will also improve your general health and reduce your risk of developing other serious health conditions, such as lung cancer and heart disease.